JPS5914081Y2 - Spherical processing equipment - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a spherical surface machining device that cuts a soft metal spherical surface with high precision.

Conventionally, various means have been applied to form a spherical surface, but as shown in Figure 1, spherical surface grinding using the principle of curve generator processing is A cup-shaped grindstone provided with an inclination θ is driven to rotate, and the workpiece a is ground to a radius of curvature R.

However, although grinding is suitable for processing hard and brittle materials, when processing soft metals, the grindstone becomes clogged, making it difficult to process with high precision.

That is, when the grindstone becomes clogged, a "peeling" phenomenon occurs, and the surface roughness deteriorates.

Further, there is a drawback that the clogging of the grindstone deteriorates its sharpness and increases the amount of heat generated during machining, resulting in a large amount of thermal deformation of the workpiece and a decrease in shape accuracy.

Additionally, there is a spherical lapping method, which poses no problem for hard and brittle materials such as lenses, but when lapping soft metals, abrasive grains become embedded, resulting in poor processing efficiency.

Furthermore, as shown in FIG.
There is one in which a rotating shaft d is provided at right angles to the front of the rotating shaft d, and a cutting tool e is attached to the rotating shaft d so that the radius of rotation of the cutting tool e becomes the radius of curvature of a spherical surface.

However, when pi) e is rotated around the rotational axis d, it is done manually and the rotational axis is supported by a pole bearing, so the accuracy is poor and high precision spherical machining is not possible. .

This idea was made in consideration of the above circumstances, and its purpose was to use static pressure air bearings for both the radial and the radial bearings of the tool rotation shaft, to improve rotation accuracy, and to improve the position of the cutting edge of the tool. The present invention aims to provide a spherical surface processing device that can easily form concave spherical surfaces and convex spherical surfaces with high accuracy through adjustment.

Hereinafter, this invention will be explained based on one embodiment shown in the drawings.

Reference numeral 1 in FIG. 3 is a surface plate, and a high-precision spindle 3 is provided on the upper part of the surface plate via a support base 2, and a workpiece A is attached to this spindle 3 so as to be rotated.

Further, a guide body 5 is horizontally fixed to the surface plate 1 via support legs 4.

A support shaft 7 is rotatably supported on a part of the guide body 5 via a journal static pressure bearing 6 .

A collar portion 8 is integrally provided at one end of the support shaft 7 that projects toward the back side of the guide body 5 and is in contact with the lower surface of the guide body 5 .

Further, a rotary table 9 is joined to the other end of the support shaft 7 protruding toward the upper surface of the guide body 5 with a flange 10 interposed therebetween.

Further, the journal static pressure bearing 6 is provided with a first thrust static pressure bearing 11, which supports the rotary table 9.

Further, a recessed portion 12 is provided at the free end of the rotary table 9 to fit into the guide body 5, and a second thrust hydrostatic bearing 13 is provided on the inner surface of the recessed portion 12.

Furthermore, a linear guide table 15 is mounted on the upper surface of the rotary table 9 via a sliding bearing 14, and is movable forward and backward with respect to the workpiece A by means of a feed screw 16.

A tool stand 17 is secured and fixed to the upper part of this linear guide table 15, and a tool 18 is attached to this tool stand 17.

On the other hand, a rotary plate 19 is fitted to the lower end of the support shaft 7, and a part of the periphery of the rotary plate 19 is linked to a drive mechanism 21 consisting of a motor via a crank rod 20.

When the spindle 3 rotates the workpiece A and the drive mechanism 21 is energized, the crank rod 2
The support shaft 7 rotates through 0.

Therefore, the rotary table 9 fixed to the support shaft 7 rotates around the support shaft 7, and the tool 18 attached to the tool stand 17 also rotates.

At this time, since the cutting edge of the tool 18 is located closer to the spindle 3 than the axis of the support shaft 7, a concave spherical surface is formed on the workpiece A, and when a convex spherical surface is formed, the tool 18 The tip η of the support shaft 7 may be moved back from the axis of the support shaft 7.

Also, settings for concave spherical surface, convex spherical surface, and radius of curvature can be made using the feed screw 16.
The linear feed table 15 may be advanced or retracted by the following steps.

As explained above, this invention has a structure in which a tool that rotates in an arcuate trajectory with a predetermined angle is positioned above the spindle that is the center of the rotation. It has become possible to easily form concave and convex spherical surfaces with a simple configuration that only requires adjusting the position of the cutting edge of the tool.

The rotary table that rotates around the support shaft is supported by a static air bearing, and the tool is attached to this rotary table via a linear guide table, so the movable parts are not in contact with each other.
It has excellent vibration-proofing effects, operates smoothly, rotates with high precision, and can perform high-precision spherical machining.

According to experiments conducted by the inventors, a high-precision spindle with a rotational accuracy (radial swing) of within 0.1 μm, a high-precision spindle with a rotational accuracy of within 0.1 μm, and a high-precision spindle with a rotational accuracy of 0.1 μm or less.
The roundness of each part is 0.7 using a rotary table within 5 μm.
It was possible to process a concave spherical surface within μm.

[Brief explanation of drawings]

1 and 2 are schematic explanatory views showing different conventional examples, and FIG. 3 is a longitudinal sectional side view showing an embodiment of this invention. 3... Spindle, 7... Support shaft, 9...
... Rotating table, 11.13 ... Thrust static pressure bearing, 15 ... Linear guide table, 1
8...Tool, A...Workpiece.

Claims (1)

[Scope of utility model registration request] A surface plate, a support leg installed on one side of the surface plate, a guide body placed on the support leg, this guide body, and a support shaft inserted through the guide body via a hydrostatic bearing mechanism. a rotary table having a concave portion into which the peripheral end portion of the guide body is fitted by a hydrostatic bearing mechanism support and inserted into one end portion of the support shaft protruding toward the upper surface side of the guide body; A linear guide table that is mounted on a rotary table and can be freely adjusted forward and backward in a direction perpendicular to the axial direction of the support shaft, and a cutting edge position on the linear guide table is located on a line that intersects the extended axis of the support shaft. a spindle mechanism installed on the other side of the surface plate to support and rotate the workpiece to be machined by the tool; and a support shaft protruding from the lower surface of the guide body. A rotary plate inserted into the other end portion, and a rotation mechanism that rotates the rotary plate and rotates the rotary table at a predetermined amplitude, and the position of the cutting edge of the tool intersects the center axis of the support shaft. A spherical surface processing device characterized in that a concave spherical surface or a convex spherical surface is formed by adjustment toward the front side or the rear side without intersecting.